The invention relates to a device for the fine adjustment of the angular rotative position of a shaft relative to a component releaseably connected thereto through a coupling bushing means which can be fixed on said shaft by means of a toothed surface uniformly provided on a periphery therebetween, and which can be positioned in cut outs of identical shape on the component by means of a further uniformly toothed surface wherein a large number of possibilities of angular adjustment between the shaft and the component are possible.
European Preliminary Publication 0,148,794 describes a device, by means of which the angular position of a steering-wheel hub relative to a steering shaft, coaxial therewith, is obtained utilizing a bushing which is arranged between the shaft and hub, and is rotationally fixed to the steering shaft by means of a set of teeth and is displaceable on this connection in an axial direction. The bushing rotates the steering wheel hub by means of helically extending tooth flanks of a further toothed connection with the hub, wherein the steering shaft is thus caused to rotate relative to the steering wheel hub.
This device makes it possible to cover a large angular range, which cannot be obtained by just changing the bushing on the steering shaft by the amount of one tooth for the exact alignment of the steering wheel hub relative to the steering shaft to which the vehicle wheels to be steered are connected. Rather, the solution described therein involves a large number of interfacing parts, and is therefore relatively expensive, since it is necessary to have both a drive for the axial displacement of the bushing and a complicated helical shape of the tooth flanks on the steering wheel hub, as well as having this complicated shape be given to the teeth of the bushing with which it engages. Moreover, the adjusting mechanism as a whole requires a large dimensional depth for the structure.
An object of the instant invention is to provide a simple means to increase the number of possibilities of angular adjustment beyond those afforded by the normal toothed connection of a steering wheel shaft to a bushing, connected co-axially and releaseably between a steering wheel hub and shaft.
The object is achieved by having a number of teeth in the toothed surface between the steering shaft and the bushing be much greater than a number of teeth in a toothed surface between the bushing and the steering wheel hub, whereupon a division of the larger number by the smaller number produces a remainder after the decimal point not equal to zero.
Simply by changing the position of the bushing on the steering shaft and also in the steering wheel hub, the total number of possible angular adjustments increases to a value which is obtained from the possibilities of angular adjustment by means of one toothed connection multiplied by the different possibilities of angular adjustment of the other toothed connection, as a result of which a sufficiently exact alignment of the steering wheel hub on the steering shaft is achieved quite simply and with low costs.
Since certain tolerances have to be allowed in the production of toothed connections, the bushing is braced by resting it frictionally against sloping faces so as to be able to transmit the steering torque if overloading occurs, as for example, due to an attempt to manipulate the steering wheel lock by over-rotating the steering wheel. The bracing can additionally be by plural faces on two flanks of the bushing.
Additionally, it is possible to have the teeth, provided between the steering wheel hub and bushing, be either radially or axially engaged. It is also desirable to have a spring bracing the bushing, as well as having the bushing and spring located between the steering wheel hub and shaft, for transporting and ease of assembly purposes.
It is also advantageous to the teeth on the steering wheel hub, which has relatively few teeth, be cast onto the steering wheel hub and be produced as unitary aluminum diecasting, since it is thereby possible to ensure production accuracy.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.